Well intervention is a critical aspect of managing brownfield assets as operators seek to optimize hydrocarbon recovery and perform maintenance work to ensure wellbore integrity. The costs of traditional workover methods and technologies, specifically in an offshore environment, can create economic barriers to the number and types of interventions that are completed in a declining field. Light well intervention technology is considered a cost effective alternative to performing rig interventions on aging subsea wells.
Operators and service providers continually seek to develop technologies and procedures that mitigate economic risk when working on these mature production wellbores. One revolution that has been in development for the past few decades involves using conventional slickline and electric line to perform light well interventions without the requirement of an offshore drilling or workover rig. This process uses a light well intervention vessel (LWIV) complete with a moonpool located mid-deck for open-sea access, a riserless pressure control package typically involving remotely operated vehicles (ROVs), and a combination of conventional slickline and electric line intervention packages. Interventions using this technology adaptation were primarily developed for the North Sea and Gulf of Mexico regions and have been widely used in those regions. However, after several years of planning, the technology has now been used for the first time to rework several wells for an operator off the east coast of Canada.
Light, riserless, well intervention technologies have been deployed in three individual wellbores offshore Canada. Multiple services were required in each of these three wellbores. Conventional slickline operations were run to prepare each of wellbores, with the retrieval of crown plugs and conventional drift runs. Operations then switched to electric line services to perform diagnostic runs followed by remedial intervention services. Once the electric line services were completed, slickline services were used for safety valve isolations and gas lift remedial work and then returning the newly configured wells back to production mode. The use of the LWIV provided the operator with an efficient intervention technique to evaluate and potentially improve well performance.